As a technique of locally processing a semiconductor substrate such as silicon (Si), there is known a technique using a focused ion beam (hereinafter, referred to as “FIB”). The focused ion beam is also used in forming a sensor element, for example, by a MEMS (Micro Electro Mechanical Systems) technique.
In addition, in the manufacturing of a MEMS sensor, there is considered a direct manufacturing using the FIB in order to shorten a TAT (Turn Around Time). In the direct manufacturing using the FIB, a workpiece is attached to the periphery again (this phenomenon will be referred to as redeposition, and a foreign matter attached by the redeposition is called a redeposited material). In a case where the redeposited material is an insulating film, and the material is attached to a wiring connection portion, a contact resistance may be increased, or a disconnection failure may be caused. On the other hand, in a case where the redeposited material is a conductor film, a short circuit failure may be caused between wirings or between electrodes. Therefore, in the direct manufacturing using the FIB, there is a need to remove the redeposited material for sure.
For example, JP-A-2013-234855 (PTL 1) discloses a technique of observing a sample by an FIB processing while emitting an ion beam to remove the redeposited material attached to a sample surface.